Storage provisioning in a data storage environment

ABSTRACT

A system, method, and computer program product for storage provisioning in a data storage environment comprising protecting, through an orchestration API, a source volume at a source site by setting the source volume to be replicated to a target volume at a target site through the use of a replication appliance; wherein the API is enabled to create network zones between the source site and the target site for replication from the source site to the target site and wherein the network zone is configured to include the replication appliance; wherein the API is enabled to mask storage devices used to store data on the source volume and the target volume.

A portion of the disclosure of this patent document may contain commandformats and other computer language listings, all of which are subjectto copyright protection. The copyright owner has no objection to thefacsimile reproduction by anyone of the patent document or the patentdisclosure, as it appears in the Patent and Trademark Office patent fileor records, but otherwise reserves all copyright rights whatsoever.

TECHNICAL FIELD

This invention relates to data replication.

RELATED APPLICATIONS

This Application is related to U.S. patent application Ser. No.13/630,455 entitled “SINGLE CONTROL PATH” filed on Sep. 28, 2012, Ser.No. 13/631,030 entitled “METHOD AND APPARATUS FOR FEDERATING A PLURALITYOF ONE BIG ARRAYS” filed on Sep. 28, 2012, Ser. No. 13/631,039 entitled“METHOD AND APPARATUS FOR AUTOMATED INFORMATION LIFECYCLE MANAGEMENTUSING A FEDERATION OF ARRAYS” filed on Sep. 28, 2012, Ser. No.13/631,055 entitled “METHOD AND APPARATUS FOR FEDERATED IDENTITY ANDAUTHENTICATION SERVICES” filed on Sep. 28, 2012, Ser. No. 13/631,190entitled “APPLICATION PROGRAMMING INTERFACE” filed on Sep. 28, 2012,Ser. No. 13/631,214 entitled “AUTOMATED POLICY BASED SCHEDULING ANDPLACEMENT OF STORAGE RESOURCES” filed on Sep. 28, 2012, Ser. No.13/631,246 entitled “DISTRIBUTED SYSTEM SOFTWARE INFRASTRUCTURE”, filedon Sep. 28, 2012, and Ser. No. 13/886,786 entitled “DISTRIBUTED WORKFLOWMANAGER” filed on even date herewith, Ser. No. 13/886,789 entitled “PORTPROVISIONING SYSTEM” filed on even date herewith, Ser. No. 13/886,892entitled “SCALABLE INDEX STORE” filed on even date herewith, Ser. No.13/886,915 entitled “SCALABLE OBJECT STORE” filed on even date herewith,and Ser. No. 13/886,644 entitled “STORAGE PROVISIONING IN A DATA STORAGEENVIRONMENT” filed on even date herewith, which are hereby incorporatedherein by reference in their entirety.

BACKGROUND

Computer data is vital to today's organizations, and a significant partof protection against disasters is focused on data protection. Assolid-state memory has advanced to the point where cost of memory hasbecome a relatively insignificant factor, organizations can afford tooperate with systems that store and process terabytes of data.

Conventional data protection systems include tape backup drives, forstoring organizational production site data on a periodic basis. Suchsystems suffer from several drawbacks. First, they require a systemshutdown during backup, since the data being backed up cannot be usedduring the backup operation. Second, they limit the points in time towhich the production site can recover. For example, if data is backed upon a daily basis, there may be several hours of lost data in the eventof a disaster. Third, the data recovery process itself takes a longtime.

Another conventional data protection system uses data replication, bycreating a copy of the organization's production site data on asecondary backup storage system, and updating the backup with changes.The backup storage system may be situated in the same physical locationas the production storage system, or in a physically remote location.Data replication systems generally operate either at the applicationlevel, at the file system level, at the hypervisor level or at the datablock level.

Current data protection systems try to provide continuous dataprotection, which enable the organization to roll back to any specifiedpoint in time within a recent history. Continuous data protectionsystems aim to satisfy two conflicting objectives, as best as possible;namely, (i) minimize the down time, in which the organization productionsite data is unavailable, during a recovery, and (ii) enable recovery asclose as possible to any specified point in time within a recenthistory.

Continuous data protection typically uses a technology referred to as“journaling,” whereby a log is kept of changes made to the backupstorage. During a recovery, the journal entries serve as successive“undo” information, enabling rollback of the backup storage to previouspoints in time. Journaling was first implemented in database systems,and was later extended to broader data protection.

One challenge to continuous data protection is the ability of a backupsite to keep pace with the data transactions of a production site,without slowing down the production site. The overhead of journalinginherently requires several data transactions at the backup site foreach data transaction at the production site. As such, when datatransactions occur at a high rate at the production site, the backupsite may not be able to finish backing up one data transaction beforethe next production site data transaction occurs. If the production siteis not forced to slow down, then necessarily a backlog of un-logged datatransactions may build up at the backup site. Without being able tosatisfactorily adapt dynamically to changing data transaction rates, acontinuous data protection system chokes and eventually forces theproduction site to shut down.

SUMMARY

A system, method, and computer program product for storage provisioningin a data storage environment comprising protecting, through anorchestration API, a source volume at a source site by setting thesource volume to be replicated to a target volume at a target sitethrough the use of a replication appliance; wherein the API is enabledto create network zones between the source site and the target site forreplication from the source site to the target site and wherein thenetwork zone is configured to include the replication appliance; whereinthe API is enabled to mask storage devices used to store data on thesource volume and the target volume.

BRIEF DESCRIPTION OF THE DRAWINGS

Objects, features, and advantages of embodiments disclosed herein may bebetter understood by referring to the following description inconjunction with the accompanying drawings. The drawings are not meantto limit the scope of the claims included herewith. For clarity, notevery element may be labeled in every figure. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingembodiments, principles, and concepts. Thus, features and advantages ofthe present disclosure will become more apparent from the followingdetailed description of exemplary embodiments thereof taken inconjunction with the accompanying drawings in which:

FIG. 1 is a simplified illustration of a data protection system, inaccordance with an embodiment of the present disclosure;

FIG. 2 is an alternative simplified illustration of a data protectionsystem, in accordance with an embodiment of the present disclosure;

FIG. 3 is a simplified example of a method for orchestrating a workflowfor an API, in accordance with an embodiment of the present disclosure;

FIG. 4 is a simplified illustration of an API discovering theconnectivity of a data protection system, in accordance with anembodiment of the present disclosure;

FIG. 5 is a simplified illustration of an API determining storage arraysin a data protection system that match an API request, in accordancewith an embodiment of the present disclosure;

FIG. 6 is a simplified illustration of an API creating volumes on thesource and target storage arrays in a data protection system that matchan API request, in accordance with an embodiment of the presentdisclosure;

FIG. 7 is a simplified illustration of an API performing network zoningin a data protection system, in accordance with an embodiment of thepresent disclosure;

FIG. 8 is a simplified illustration of an API masking storage devices ina data protection system, in accordance with an embodiment of thepresent disclosure;

FIG. 9 is a simplified illustration of an API creating a protectionrelationship between volumes in a data protection system, in accordancewith an embodiment of the present disclosure;

FIG. 10 is a simplified example of a method for orchestrating a workflowfor an API, in accordance with an embodiment of the present disclosure;

FIG. 11 is an example of an embodiment of an apparatus that may utilizethe techniques described herein, in accordance with an embodiment of thepresent disclosure; and

FIG. 12 is an example of a method embodied on a computer readablestorage medium that may utilize the techniques described herein, inaccordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

Typically, storage (or data) protection is provided by any of a seriesof technologies that makes a copy of an original set of data to targetdevices. Generally, the copy of the data may be used if an event such asdata failure occurs such as, for example, when the original copy of datais destroyed, corrupted, or otherwise unavailable. Conventionally,different strategies may be used to provide data protection fordifferent types of failures that can occur. Usually, some strategies arecontinuous (source and targets are kept in sync), while others aresimply refreshed periodically.

Current solutions to deploy such data protection strategies arepredominantly documented procedures that must be executed by an ITprofessional each time a request for new storage is submitted.Similarly, typical clean-up of such resources is also a documentedprocedure, but is conventionally neglected until storage or protectionresources become scarce. Usually, partially automated solutions to partsof the strategy are sometimes written in the form of executable scriptsthat are built in-house or by a service professional that is tailor-madeto the specific infrastructure and needs of the datacenter. Generally,the solutions are difficult to maintain and inflexible to theconstantly-changing datacenter.

In certain embodiments, the current disclosure may enable creation of anecosystem of centralized global datacenter management, regardless of thestorage manufacturer, protocol, and geographic disparity. In someembodiments, an IT professional may be enabled to configure a datacenterto leverage a unified management platform to perform various tasks viaone interface, such as a web portal, without having to use differentelement managers or CLIs. In certain embodiments, an API may be enabledthat can automatically create a protected storage volume on a sourcesite replicated on a target volume on a target site.

Conventionally, a request to create a new two terabyte volume replicatedvolume, there may be twenty-four steps for a typical IT administrator.Conventional techniques also may require manipulation of severaldifferent APIs (Solutions Enabler API, switch) and GUIs.

In most embodiments, the current disclosure enables the process ofcreating a replicated volume with a simple set of input. In someembodiments, the inputs may include such as where the volume shouldexist and how the volume should be protected. In at least someembodiments, an orchestration API is enabled to discover whichreplication appliances are connected to which storage arrays. In otherembodiments, an orchestration API may be able to determine what storagearrays or storage pools are able to satisfy which storage requests. Infurther embodiments, an orchestration API may be able to create volumesto satisfy a storage request sent to the storage array. In at least someembodiments, creating volumes may include creating a volume at both thesource and target site as well as creating supplemental volumes, such asjournal volumes, for replication. In certain embodiments, the API mayorchestrate creating zones for storage arrays and replicationappliances. In other embodiments, the orchestration SPI may be enabledto mask created volumes to a respective replication appliance clusternode. In still other embodiments, the orchestration API may createconsistency groups for the replication appliance.

In some embodiments, the functionality orchestrated by the orchestrationAPI may be performed in parallel. In other embodiments, clusterload-balancing within the logical array cluster may be enabled. In aparticular embodiment, when creating 20 volumes, the request to createeach volume may occur in parallel. In most embodiments, theorchestration of each sub-step may be carried out in an order-dependentand efficient way. In most embodiments, this may ensure the sourcevolume(s) is created in an efficient manner.

In other embodiments, system configuration may be enabled to providedata protection in an automated fashion without requiring a user tospecify the details of such a configuration. In most embodiments, a usermay define operational and service requirements and the techniques ofthe current disclosure may enable the system to be configured to meetthe user's operational and service requirements. In certain embodiments,the current disclosure may enable a unified approach to handle theseveral layers of abstraction in the mapping an applications to a disk.

In most embodiments, the current disclosure may enable improved levelsof data protection through policy controls and automation of protectiontasks of customers' storage. In some embodiments, the current disclosuremay enable replacement of a plethora of traditional IT-generated scriptsand manual documented procedures.

In at least some embodiments, the current disclosure may enable theautomation of storage protection. In most embodiments, the currentdisclosure may enable engine to orchestrate of a series of steps thatcreate and protect storage across heterogeneous storage technologies viaa varied selection of protection mechanisms.

In certain embodiments, the current disclosure may free administratorsfrom manually creating data protection for thousands of LUNS and volumesacross hundreds of systems by automating these tasks. In someembodiments, components of IT environments such as storage arrays,protection appliances, storage switches, and IP networks may beconsolidated into a single framework presenting a comprehensive view ofthe data protection environment. In at least some embodiments, an APImay provide connectivity mappings of storage arrays and protectionappliances, allowing user interfaces to enforce good decision-making onthe part of the requester. In alternative embodiments, a UI may masksthe complexity of configuring and managing underlying tasks such aszoning, volume creation, and protection enablement. In otherembodiments, an IT professional or cloud consumer may be able toimplement protection of a storage environment without the burden ofstorage level tasks. The following may be helpful in understanding thespecification and claims:

BACKUP SITE—may be a facility where replicated production site data isstored; the backup site may be located in a remote site or at the samelocation as the production site; a backup site may be a virtual orphysical site

CLONE—a clone may be a copy or clone of the image or images, drive ordrives of a first location at a second location;

DELTA MARKING STREAM—may mean the tracking of the delta between theproduction and replication site, which may contain the meta data ofchanged locations, the delta marking stream may be kept persistently onthe journal at the production site of the replication, based on thedelta marking data the DPA knows which locations are different betweenthe production and the replica and transfers them to the replica to makeboth sites identical.

DPA—may be Data Protection Appliance a computer or a cluster ofcomputers, or a set of processes that serve as a data protectionappliance, responsible for data protection services including inter aliadata replication of a storage system, and journaling of I/O requestsissued by a host computer to the storage system; The DPA may be aphysical device, a virtual device running, or may be a combination of avirtual and physical device.

RPA—may be replication protection appliance, is another name for DPA. AnRPA may be a virtual DPA or a physical DPA.

HOST—may be at least one computer or networks of computers that runs atleast one data processing application that issues I/O requests to one ormore storage systems; a host is an initiator with a SAN; a host may be avirtual machine

HOST DEVICE—may be an internal interface in a host, to a logical storageunit;

IMAGE—may be a copy of a logical storage unit at a specific point intime;

INITIATOR—may be a node in a SAN that issues I/O requests;

JOURNAL—may be a record of write transactions issued to a storagesystem; used to maintain a duplicate storage system, and to rollback theduplicate storage system to a previous point in time;

LOGICAL UNIT—may be a logical entity provided by a storage system foraccessing data from the storage system;

LUN—may be a logical unit number for identifying a logical unit; mayalso refer to one or more virtual disks or virtual LUNs, which maycorrespond to one or more Virtual Machines.

Management and deployment tools—may provide the means to deploy, controland manage the RP solution through the virtual environment managementtools

PHYSICAL STORAGE UNIT—may be a physical entity, such as a disk or anarray of disks, for storing data in storage locations that can beaccessed by address;

PRODUCTION SITE—may be a facility where one or more host computers rundata processing applications that write data to a storage system andread data from the storage system; may be a virtual or physical site

SAN—may be a storage area network of nodes that send and receive I/O andother requests, each node in the network being an initiator or a target,or both an initiator and a target;

SOURCE SIDE—may be a transmitter of data within a data replicationworkflow, during normal operation a production site is the source side;and during data recovery a backup site is the source side; may be avirtual or physical site

SNAPSHOT—a Snapshot may refer to differential representations of animage, i.e. the snapshot may have pointers to the original volume, andmay point to log volumes for changed locations. Snapshots may becombined into a snapshot array, which may represent different imagesover a time period.

STORAGE SYSTEM—may be a SAN entity that provides multiple logical unitsfor access by multiple SAN initiators

TARGET—may be a node in a SAN that replies to I/O requests;

TARGET SIDE—may be a receiver of data within a data replicationworkflow; during normal operation a back site is the target side, andduring data recovery a production site is the target side; may be avirtual or physical site

WAN—may be a wide area network that connects local networks and enablesthem to communicate with one another, such as the Internet.

SPLITTER/PROTECTION AGENT: may be an agent running either on aproduction host a switch or a storage array which can intercept IO andsplit them to a DPA and to the storage array, fail IO redirect IO or doany other manipulation to the IO; the splitter or protection agent maybe used in both physical and virtual systems. The splitter may be in theIO stack of a system and may be located in the hypervisor for virtualmachines. May be referred to herein as an Open Replicator Splitter(ORS).

VIRTUAL VOLUME: may be a volume which is exposed to host by avirtualization layer, the virtual volume may be spanned across more thanone site and or volumes

VASA: may be a set of vCenter providers that allow an administrator tomanage storage

Virtualization filter appliance (VFA): may be a layer in the hypervisorthat has the ability intercepts and split IO from a VM being written toa virtual disk. In some embodiments, the VFA may be running on a VM in ahypervisor This is an out of mechanism that allows storage managementover web based APIs.

VVOL-filter—may be a VM utilizing a specialized Virtual machine, whichmay provide an infrastructure that allows for introducing a “devicedriver” into the virtualized IO stack provided by the Virtual machine

Virtual RPA (vRPA)/Virtual DPA (vDPA): may be an DPA running in a VM.

VASA may be vSphere Storage application program interfaces (APIs) forStorage Awareness.

DISTRIBUTED MIRROR: may be a mirror of a volume across distance, eithermetro or geo, which is accessible at all sites.

BLOCK VIRTUALIZATION: may be a layer, which takes backend storagevolumes and by slicing concatenation and striping create a new set ofvolumes, which serve as base volumes or devices in the virtualizationlayer

MARKING ON SPLITTER: may be a mode in a splitter where intercepted IOsare not split to an appliance and the storage, but changes (meta data)are tracked in a list and/or a bitmap and I/O is immediately sent todown the IO stack.

FAIL ALL MODE: may be a mode of a volume in the splitter where all writeand read IOs intercepted by the splitter are failed to the host, butother SCSI commands like read capacity are served.

GLOBAL FAIL ALL MODE: may be a mode of a volume in the virtual layerwhere all write and read IOs virtual layer are failed to the host, butother SCSI commands like read capacity are served.

LOGGED ACCESS: may be an access method provided by the appliance and thesplitter, in which the appliance rolls the volumes of the consistencygroup to the point in time the user requested and let the host accessthe volumes in a copy on first write base.

VIRTUAL ACCESS: may be an access method provided by the appliance andthe splitter, in which the appliance exposes a virtual volume from aspecific point in time to the host, the data for the virtual volume ispartially stored on the remote copy and partially stored on the journal.

CDP: Continuous Data Protection, may refer to a full replica of a volumeor a set of volumes along with a journal which allows any point in timeaccess, the CDP copy is at the same site, and maybe the same storagearray of the production site

CRR: Continuous Remote Replica may refer to a full replica of a volumeor a set of volumes along with a journal which allows any point in timeaccess at a site remote to the production volume and on a separatestorage array.

A description of journaling and some techniques associated withjournaling may be described in the patent titled METHODS AND APPARATUSFOR OPTIMAL JOURNALING FOR CONTINUOUS DATA REPLICATION and with U.S.Pat. No. 7,516,287, and METHODS AND APPARATUS FOR OPTIMAL JOURNALING FORCONTINUOUS DATA REPLICATION and with U.S. Pat. No. 8,332,687, which arehereby incorporated by reference. A description of synchronous andasynchronous replication may be described in the patent titledDYNAMICALLY SWITCHING BETWEEN SYNCHRONOUS AND ASYNCHRONOUS REPLICATIONand with U.S. Pat. No. 8,341,115, which is hereby incorporated byreference.

A discussion of image access may be found in U.S. patent applicationSer. No. 12/969,903 entitled “DYNAMIC LUN RESIZING IN A REPLICATIONENVIRONMENT” filed on Dec. 16, 2010 assigned to EMC Corp., which ishereby incorporated by reference.

Description of Embodiments Using of a Five State Journaling Process

Reference is now made to FIG. 1, which is a simplified illustration of adata protection system 100, in accordance with an embodiment of thepresent invention. Shown in FIG. 1 are two sites; Site I, which is aproduction site, on the right, and Site II, which is a backup site, onthe left. Under normal operation the production site is the source sideof system 100, and the backup site is the target side of the system. Thebackup site is responsible for replicating production site data.Additionally, the backup site enables rollback of Site I data to anearlier pointing time, which may be used in the event of data corruptionof a disaster, or alternatively in order to view or to access data froman earlier point in time.

During normal operations, the direction of replicate data flow goes fromsource side to target side. It is possible, however, for a user toreverse the direction of replicate data flow, in which case Site Istarts to behave as a target backup site, and Site II starts to behaveas a source production site. Such change of replication direction isreferred to as a “failover”. A failover may be performed in the event ofa disaster at the production site, or for other reasons. In some dataarchitectures, Site I or Site II behaves as a production site for aportion of stored data, and behaves simultaneously as a backup site foranother portion of stored data. In some data architectures, a portion ofstored data is replicated to a backup site, and another portion is not.

The production site and the backup site may be remote from one another,or they may both be situated at a common site, local to one another.Local data protection has the advantage of minimizing data lag betweentarget and source, and remote data protection has the advantage is beingrobust in the event that a disaster occurs at the source side.

The source and target sides communicate via a wide area network (WAN)128, although other types of networks are also adaptable for use withthe present invention.

In accordance with an embodiment of the present invention, each side ofsystem 100 includes three major components coupled via a storage areanetwork (SAN); namely, (i) a storage system, (ii) a host computer, and(iii) a data protection appliance (DPA). Specifically with reference toFIG. 1, the source side SAN includes a source host computer 104, asource storage system 108, and a source DPA 112. Similarly, the targetside SAN includes a target host computer 116, a target storage system120, and a target DPA 124.

Generally, a SAN includes one or more devices, referred to as “nodes”. Anode in a SAN may be an “initiator” or a “target”, or both. An initiatornode is a device that is able to initiate requests to one or more otherdevices; and a target node is a device that is able to reply torequests, such as SCSI commands, sent by an initiator node. A SAN mayalso include network switches, such as fiber channel switches. Thecommunication links between each host computer and its correspondingstorage system may be any appropriate medium suitable for data transfer,such as fiber communication channel links.

In an embodiment of the present invention, the host communicates withits corresponding storage system using small computer system interface(SCSI) commands.

System 100 includes source storage system 108 and target storage system120. Each storage system includes physical storage units for storingdata, such as disks or arrays of disks. Typically, storage systems 108and 120 are target nodes. In order to enable initiators to send requeststo storage system 108, storage system 108 exposes one or more logicalunits (LU) to which commands are issued. Thus, storage systems 108 and120 are SAN entities that provide multiple logical units for access bymultiple SAN initiators.

Logical units are a logical entity provided by a storage system, foraccessing data stored in the storage system. A logical unit isidentified by a unique logical unit number (LUN). In an embodiment ofthe present invention, storage system 108 exposes a logical unit 136,designated as LU A, and storage system 120 exposes a logical unit 156,designated as LU B.

In an embodiment of the present invention, LU B is used for replicatingLU A. As such, LU B is generated as a copy of LU A. In one embodiment,LU B is configured so that its size is identical to the size of LU A.Thus for LU A, storage system 120 serves as a backup for source sidestorage system 108. Alternatively, as mentioned hereinabove, somelogical units of storage system 120 may be used to back up logical unitsof storage system 108, and other logical units of storage system 120 maybe used for other purposes. Moreover, in certain embodiments of thepresent invention, there is symmetric replication whereby some logicalunits of storage system 108 are used for replicating logical units ofstorage system 120, and other logical units of storage system 120 areused for replicating other logical units of storage system 108.

System 100 includes a source side host computer 104 and a target sidehost computer 116. A host computer may be one computer, or a pluralityof computers, or a network of distributed computers, each computer mayinclude inter alia a conventional CPU, volatile and non-volatile memory,a data bus, an I/O interface, a display interface and a networkinterface. Generally a host computer runs at least one data processingapplication, such as a database application and an e-mail server.

Generally, an operating system of a host computer creates a host devicefor each logical unit exposed by a storage system in the host computerSAN. A host device is a logical entity in a host computer, through whicha host computer may access a logical unit. In an embodiment of thepresent invention, host device 104 identifies LU A and generates acorresponding host device 140, designated as Device A, through which itcan access LU A. Similarly, host computer 116 identifies LU B andgenerates a corresponding device 160, designated as Device B.

In an embodiment of the present invention, in the course of continuousoperation, host computer 104 is a SAN initiator that issues I/O requests(write/read operations) through host device 140 to LU A using, forexample, SCSI commands. Such requests are generally transmitted to LU Awith an address that includes a specific device identifier, an offsetwithin the device, and a data size. Offsets are generally aligned to 512byte blocks. The average size of a write operation issued by hostcomputer 104 may be, for example, 10 kilobytes (KB); i.e., 20 blocks.For an I/O rate of 50 megabytes (MB) per second, this corresponds toapproximately 5,000 write transactions per second.

System 100 includes two data protection appliances, a source side DPA112 and a target side DPA 124. A DPA performs various data protectionservices, such as data replication of a storage system, and journalingof I/O requests issued by a host computer to source side storage systemdata. As explained in detail hereinbelow, when acting as a target sideDPA, a DPA may also enable rollback of data to an earlier point in time,and processing of rolled back data at the target site. Each DPA 112 and124 is a computer that includes inter alia one or more conventional CPUsand internal memory.

For additional safety precaution, each DPA is a cluster of suchcomputers. Use of a cluster ensures that if a DPA computer is down, thenthe DPA functionality switches over to another computer. The DPAcomputers within a DPA cluster communicate with one another using atleast one communication link suitable for data transfer via fiberchannel or IP based protocols, or such other transfer protocol. Onecomputer from the DPA cluster serves as the DPA leader. The DPA clusterleader coordinates between the computers in the cluster, and may alsoperform other tasks that require coordination between the computers,such as load balancing.

In the architecture illustrated in FIG. 1, DPA 112 and DPA 124 arestandalone devices integrated within a SAN. Alternatively, each of DPA112 and DPA 124 may be integrated into storage system 108 and storagesystem 120, respectively, or integrated into host computer 104 and hostcomputer 116, respectively. Both DPAs communicate with their respectivehost computers through communication lines such as fiber channels using,for example, SCSI commands.

In accordance with an embodiment of the present invention, DPAs 112 and124 are configured to act as initiators in the SAN; i.e., they can issueI/O requests using, for example, SCSI commands, to access logical unitson their respective storage systems. DPA 112 and DPA 124 are alsoconfigured with the necessary functionality to act as targets; i.e., toreply to I/O requests, such as SCSI commands, issued by other initiatorsin the SAN, including inter alia their respective host computers 104 and116. Being target nodes, DPA 112 and DPA 124 may dynamically expose orremove one or more logical units.

As described hereinabove, Site I and Site II may each behavesimultaneously as a production site and a backup site for differentlogical units. As such, DPA 112 and DPA 124 may each behave as a sourceDPA for some logical units and as a target DPA for other logical units,at the same time.

In accordance with an embodiment of the present invention, host computer104 and host computer 116 include protection agents 144 and 164,respectively. Protection agents 144 and 164 intercept SCSI commandsissued by their respective host computers, via host devices to logicalunits that are accessible to the host computers. In accordance with anembodiment of the present invention, a data protection agent may act onan intercepted SCSI commands issued to a logical unit, in one of thefollowing ways:

Send the SCSI commands to its intended logical unit.

Redirect the SCSI command to another logical unit.

Split the SCSI command by sending it first to the respective DPA. Afterthe DPA returns an acknowledgement, send the SCSI command to itsintended logical unit.

Fail a SCSI command by returning an error return code.

Delay a SCSI command by not returning an acknowledgement to therespective host computer.

A protection agent may handle different SCSI commands, differently,according to the type of the command. For example, a SCSI commandinquiring about the size of a certain logical unit may be sent directlyto that logical unit, while a SCSI write command may be split and sentfirst to a DPA associated with the agent. A protection agent may alsochange its behavior for handling SCSI commands, for example as a resultof an instruction received from the DPA.

Specifically, the behavior of a protection agent for a certain hostdevice generally corresponds to the behavior of its associated DPA withrespect to the logical unit of the host device. When a DPA behaves as asource site DPA for a certain logical unit, then during normal course ofoperation, the associated protection agent splits I/O requests issued bya host computer to the host device corresponding to that logical unit.Similarly, when a DPA behaves as a target device for a certain logicalunit, then during normal course of operation, the associated protectionagent fails I/O requests issued by host computer to the host devicecorresponding to that logical unit.

Communication between protection agents and their respective DPAs mayuse any protocol suitable for data transfer within a SAN, such as fiberchannel, or SCSI over fiber channel. The communication may be direct, orvia a logical unit exposed by the DPA. In an embodiment of the presentinvention, protection agents communicate with their respective DPAs bysending SCSI commands over fiber channel.

In an embodiment of the present invention, protection agents 144 and 164are drivers located in their respective host computers 104 and 116.Alternatively, a protection agent may also be located in a fiber channelswitch, or in any other device situated in a data path between a hostcomputer and a storage system.

What follows is a detailed description of system behavior under normalproduction mode, and under recovery mode.

In accordance with an embodiment of the present invention, in productionmode DPA 112 acts as a source site DPA for LU A. Thus, protection agent144 is configured to act as a source side protection agent; i.e., as asplitter for host device A. Specifically, protection agent 144replicates SCSI I/O requests. A replicated SCSI I/O request is sent toDPA 112. After receiving an acknowledgement from DPA 124, protectionagent 144 then sends the SCSI I/O request to LU A. Only after receivinga second acknowledgement from storage system 108 may host computer 104initiate another I/O request.

When DPA 112 receives a replicated SCSI write request from dataprotection agent 144, DPA 112 transmits certain I/O informationcharacterizing the write request, packaged as a “write transaction”,over WAN 128 to DPA 124 on the target side, for journaling and forincorporation within target storage system 120.

DPA 112 may send its write transactions to DPA 124 using a variety ofmodes of transmission, including inter alia (i) a synchronous mode, (ii)an asynchronous mode, and (iii) a snapshot mode. In synchronous mode,DPA 112 sends each write transaction to DPA 124, receives back anacknowledgement from DPA 124, and in turns sends an acknowledgement backto protection agent 144. Protection agent 144 waits until receipt ofsuch acknowledgement before sending the SCSI write request to LU A.

In asynchronous mode, DPA 112 sends an acknowledgement to protectionagent 144 upon receipt of each I/O request, before receiving anacknowledgement back from DPA 124.

In snapshot mode, DPA 112 receives several I/O requests and combinesthem into an aggregate “snapshot” of all write activity performed in themultiple I/O requests, and sends the snapshot to DPA 124, for journalingand for incorporation in target storage system 120. In snapshot mode DPA112 also sends an acknowledgement to protection agent 144 upon receiptof each I/O request, before receiving an acknowledgement back from DPA124.

For the sake of clarity, the ensuing discussion assumes that informationis transmitted at write-by-write granularity.

While in production mode, DPA 124 receives replicated data of LU A fromDPA 112, and performs journaling and writing to storage system 120. Whenapplying write operations to storage system 120, DPA 124 acts as aninitiator, and sends SCSI commands to LU B.

During a recovery mode, DPA 124 undoes the write transactions in thejournal, so as to restore storage system 120 to the state it was at, atan earlier time.

As described hereinabove, in accordance with an embodiment of thepresent invention, LU B is used as a backup of LU A. As such, duringnormal production mode, while data written to LU A by host computer 104is replicated from LU A to LU B, host computer 116 should not be sendingI/O requests to LU B. To prevent such I/O requests from being sent,protection agent 164 acts as a target site protection agent for hostDevice B and fails I/O requests sent from host computer 116 to LU Bthrough host Device B.

In accordance with an embodiment of the present invention, targetstorage system 120 exposes a logical unit 176, referred to as a “journalLU”, for maintaining a history of write transactions made to LU B,referred to as a “journal”. Alternatively, journal LU 176 may be stripedover several logical units, or may reside within all of or a portion ofanother logical unit. DPA 124 includes a journal processor 180 formanaging the journal.

Refer now to the example embodiment of FIG. 2. The example embodiment ofFIG. 2 shows a configuration for a source site and a target site, withLUNS at the source site being replicated through replication appliancesto the target site. Source site 205 has LUN 210 and LUN 215. Source 205also has replication appliance, replication appliance 225, which hasjournal 227, and replication appliance 230 with journal 232. LUN 210 isbeing replicated by replication appliance 225 and LUN 215 is beingreplicated by replication appliance 230. LUN 210 is stored on storagearray 235 and LUN 215 is stored on storage array 240. Replicationappliance 220 may be replicating a LUN on source site 205 or may beavailable to replicate a LUN yet to be created.

Replication appliance 225 and replication appliance 230 are replicatingLUNS 210 and 215, respectively using network 247 and WAN 249 to targetsite 250. Replication appliance 265, which has journal 267, andreplication appliance 270 with journal 272 receive IOs from replicationappliances 225 and 250 on source 205 through WAN 249. Replicationappliance 265 replicates LUN 210 to LUN 255 stored on storage array 280using Network 248. Using Network 248, replication appliance 270replicates LUN 215 on LUN 260, which is stored on storage array 285.Replication appliance 275 may be replicating a LUN or may be availableto replicate a future created LUN. Conventionally, setting up thereplication environment of FIG. 2 may require an IT administrator oruser to take a plurality of steps.

Refer now to the example embodiment of FIG. 3, which represents anorchestration process which enables an IT administrator or use toexecute a single API request, where that API requests orchestrates andperforms the steps to provision and network a replicated storage volumein a data storage environment.

In the embodiment of FIG. 3, storage size, storage protocol, sourcelocation, and target location are provided as inputs to storage API 305.The orchestration API 305 then performs a series of orchestration stepsto create a replicated volume. Connectivity phase 310 discovers theconnectivity of storage arrays and replication appliance in a datastorage environment. Storage placement phase 315 finds storage arraysthat match the API request and connectivity from source to targets.Storage creation phase 320 creates volumes on the source and targetarrays in response to the parameters of the API request. Storage networkmanagement phase 325 performs zoning operation from arrays to protectionappliances (replication appliances). Storage expose phase 320 masksstorage devices to protection appliance. Protection creation phase 335creates a protection relationship between volumes. Note however, incertain embodiments, certain orchestration steps may be omitted asspecified by API 305. In certain embodiments, the replication appliancesor protection appliances may be EMC's RecoverPoint product.

Refer now to the example embodiments of FIGS. 4 and 10, showingorchestration API 400 discovering connectivity between storage arrays435, 440, 445 and replication appliances 420, 425, and 430 andreplication appliances 465, 470, and 475 with storage arrays 480, 485,and 490 (step 1005). In this embodiment, replication appliance 420 isconnected to storage array 435 and storage array 445. Replicationappliance 425 is connected to storage array 435 and 440. Replicationappliance 430 is connected to storage arrays 440 and 445. Replicationappliance 475 is connected to storage arrays 480 and 485. Replicationstorage array 470 is connected to storage arrays 480 and 490.Replication appliance 465 is connected to storage arrays 485 and 490. Inthe embodiment of FIG. 4, the replication appliances are connected tothe storage arrays through a network, such as network 447 and network448.

In certain embodiments, the replication appliances may be registeredwith orchestration API. In some embodiments, registration of thereplication appliances with the orchestration API may occur during setup of the source and target sites. In most embodiments, the replicationappliance may be registered before the orchestration API is invoked. Inat least some embodiments, a network address, username and password maybe provided during set-up of the API. In most embodiments orchestrationAPI may contact the common interface to determine what arrays areavailable at the source and target.

Refer now to the example embodiments of FIG. 5 and FIG. 10, which showorchestration API 500 determining which storage arrays and replicationappliances satisfy the parameters of the API request (Step 1010). In theexample embodiment of FIG. 5, orchestration API 500 has determined thatstorage array 535 and replication appliance 530 satisfy the parametersrequest on source 505. Orchestration API 500 has determined thatreplication appliance 575 and storage array on 590 satisfy the APIparameters on target site 550.

Note in the embodiments of FIGS. 5 and 10 that storage arrays 540, 545,580, and 585 and replication appliances 520, 525, 570, and 565 werefound to not satisfy the storage request. In other embodiments,orchestration API may identify multiple arrays and replicationappliances that may satisfy the storage request. In some embodiments,where there are multiple replication appliances or storage arrays, theorchestration API may choose the best fitting replication appliance andor storage array based on the inputted information in the API. In otherembodiments, orchestration API may request further input from anotherAPI or a user to determine which replication appliance and or storagearray to use. In certain embodiments, a determination may be made basedon load balancing parameters to choose the best replication applianceand array.

Refer now to the example embodiments of FIGS. 6 and 10, which illustrateorchestration API 600 creating storage for the request (Step 1015).Orchestration API 500 uses common interface 607 on source 605 to createLUN 610 on storage array 635. Orchestration API 600 also uses commoninterface 607 to create a journal for use by replication appliance 630in replicating LUN 610. Orchestration API 600 uses common interface 657to create LUN 655 on storage array 690 for use in replicating LUN 610.Orchestration API 600 creates journal 677 for replication appliance 675and journal 632 for replication appliance 630. In these embodiments,replication appliances 625 and 670 may not be used for replication ofLUNS 610 and 655. In some embodiments, a journal may be created on thesame storage array as the LUN being replicated. In other embodiments, ajournal may be created on a different storage array than the LUN beingreplicated. In certain embodiments, the common interface may be aStorage Management Interface system (SMIS).

Refer now to the example embodiments of FIGS. 7 and 10, which illustrateorchestration API 700 performing zoning (step 1020). In theseembodiments, orchestration API 700 uses network 747 to ensure thatstorage array 735 can communicate with replication appliance 730, thatreplication appliance 775 can communicate with storage array 790. Incertain embodiments, orchestration API may be enabled to createconnectivity between replication appliances and storage arrays. In someembodiments, the orchestration API's ability to create connectivity maydepend on whether one or more switches are in the source and targetenvironments.

Refer now to the example embodiments of FIGS. 8 and 10, which illustrateorchestration API 800 masking storage (step 1025). In these embodiments,orchestration API ensures that replication appliance 830 can communicatewith LUN 810 and that replication appliance 875 can communicate with LUN855. In certain embodiments, masking may add the LUNS into a storagegroup. In certain embodiments, ports of a replication appliance may bemarried to the LUN on the array.

Refer now to the example embodiments of FIGS. 9 and 10, which illustrateorchestration API 900 creating protection for storage (step 1030). Inthese figures, orchestration API ensures that IOs to LUN 910 are splitto replication appliance 930, IO from replication appliance 930 is sentto replication appliance 975, and that replication appliance 975replicates the IO to LUN 955.

In further embodiments, an orchestration API may be part of a larger APIor coordination API. In some embodiments, an orchestration API mayrequest input from a large API or Orchestration engine. In otherembodiments, an orchestration API may request input from a user. Instill further embodiments, an orchestration API may be one of a set ofother orchestration APIs, wherein each of the set of orchestration APIsoffer different orchestration functionality. In of these embodiments,the set of orchestration APIs may be combined with an overallOrchestration or Engine layer which may coordinate requests between theset of orchestration APIs.

The methods and apparatus of this invention may take the form, at leastpartially, of program code (i.e., instructions) embodied in tangiblemedia, such as floppy diskettes, CD-ROMs, hard drives, random access orread only-memory, or any other machine-readable storage medium. When theprogram code is loaded into and executed by a machine, such as thecomputer of FIG. 11 the machine becomes an apparatus for practicing theinvention. When implemented on one or more general-purpose processors,the program code combines with such a processor 1103 to provide a uniqueapparatus that operates analogously to specific logic circuits. As sucha general purpose digital machine can be transformed into a specialpurpose digital machine. FIG. 12 shows Program Logic 1234 embodied on acomputer-readable medium 1230 as shown, and wherein the Logic is encodedin computer-executable code configured for carrying out the reservationservice process of this invention and thereby forming a Computer ProgramProduct 1200. The logic 1234 may be the same logic 1140 on memory 1104loaded on processor 1103. The program logic may also be embodied insoftware modules, as modules, or as hardware modules.

The logic for carrying out the method may be embodied as part of thesystem described below, which is useful for carrying out a methoddescribed with reference to embodiments shown in, for example, FIG. 3and FIG. 10. For purposes of illustrating the present invention, theinvention is described as embodied in a specific configuration and usingspecial logical arrangements, but one skilled in the art will appreciatethat the device is not limited to the specific configuration but ratheronly by the claims included with this specification.

Although the foregoing invention has been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications may be practiced within the scope of theappended claims. Accordingly, the present implementations are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

What is claimed is:
 1. A system for storage provisioning in a datastorage environment, the system comprising: an orchestration API; andcomputer-executable program code operating in memory coupled with aprocessor in communication with a database, wherein thecomputer-executable program code is configured to enable a processor toexecute logic to enable: receiving, through the orchestration API, arequest to create a replicated volume, wherein the request comprises asource volume size, a source site, and a source volume protocol, whereinthe source site indicates a location at which an uncreated source volumeis to be created; based on the request, protecting, through theorchestration API, a source volume at the source site by setting thesource volume to be replicated to a target volume at a target sitethrough the use of a replication appliance; wherein the API is enabledto create network zones between the source site and the target site forreplication from the source site to the target site and wherein thenetwork zone is configured to include the replication appliance; whereinthe API is enabled to mask storage devices used to store data on thesource volume and the target volume to a respective replicationappliance cluster node.
 2. The system of claim 1 wherein theorchestration API is enabled to: determine connectivity of one or morereplication appliances, wherein the replication appliances include thereplication appliance, and storage arrays; wherein at least a firststorage array of the storage arrays is on the source site and wherein atleast a second storage array of the storage arrays is on the targetsite; and wherein the storage arrays comprise the storage devices; anddetermine configurations of the one or more storage arrays and one ormore replication volumes to match an API request for protecting thesource volume with the target volume inputted to the orchestration API.3. The system of claim 2 wherein the orchestration API is enabled tocreate the source volume on the first storage array and creating thetarget volume on the target site by interacting with the first storagearray on the source site and the second storage array on the target sitethrough a common storage interface.
 4. The system of claim 3 wherein anAPI request to create a replicated volume with a set of parameters isenabled to function with a required set of parameters consistingessentially of the storage size, storage protocol, and source location.5. The system of claim 2 wherein the orchestration API is enabled todetermine a best set of the configurations of the one or more storagearrays and one or more replication volumes; wherein if the best set is aset of one the orchestration API uses that configuration for thereplication; and wherein if the best set has multiple configurationsrequesting input as to which configuration to use in the replication. 6.The system of claim 4 wherein the API request is enabled to functionwith a set of parameters including a target site; wherein adetermination is made whether the target site has been included in theAPI request; and wherein the API is enabled to choose the target sitebased on a negative determination of target site included.
 7. A computerimplemented method comprising: receiving, through an orchestration API,a request to create a replicated volume, wherein the request comprises asource volume size, a source site, and a source volume protocol, whereinthe source site indicates a location at which an uncreated source volumeis to be created; based on the request, protecting, through theorchestration API, a source volume at the source site by setting thesource volume to be replicated to a target volume at a target sitethrough the use of a replication appliance; wherein the API is enabledto create network zones between the source site and the target site forreplication from the source site to the target site and wherein thenetwork zone is configured to include the replication appliance; whereinthe API is enabled to mask storage devices used to store data on thesource volume and the target volume to a respective replicationappliance cluster node.
 8. The method of claim 1 further comprising:determining connectivity of one or more replication appliances, whereinthe replication appliances include the replication appliance, andstorage arrays; wherein at least a first storage array of the storagearrays is on the source site and wherein at least a second storage arrayof the storage arrays is on the target site; and wherein the storagearrays comprise the storage devices; and determining configurations ofthe one or more storage arrays and one or more replication volumes tomatch an API request for protecting the source volume with the targetvolume inputted to the orchestration API.
 9. The method of claim 2wherein the orchestration API is enabled to create the source volume onthe first storage array and creating the target volume on the targetsite by interacting with the first storage array on the source site andthe second storage array on the target site through a common storageinterface.
 10. The method of claim 3 wherein an API request to theorchestration API to create a replicated volume with a set of parametersis enabled to function with a required set of parameters consistingessentially of the storage size, storage protocol, and source location.11. The method of claim 2 wherein the orchestration API is enabled todetermine a best set of the configurations of the one or more storagearrays and one or more replication volumes; wherein if the best set is aset of one the orchestration API uses that configuration for thereplication; and wherein if the best set has multiple configurationsrequesting input as to which configuration to use in the replication.12. The method of claim 4 wherein the API request is enabled to functionwith a set of parameters including a target site; wherein adetermination is made whether the target site has been included in theAPI request; and wherein the API is enabled to choose the target sitebased on a negative determination of target site included.
 13. Acomputer program product comprising: a non-transitory computer readablemedium encoded with computer executable program, the code enabling:receiving, through an orchestration API, a request to create areplicated volume, wherein the request comprises a source volume size, asource site, and a source volume protocol, wherein the source siteindicates a location at which an uncreated source volume is to becreated; based on the request, protecting, through the orchestrationAPI, a source volume at the source site by setting the source volume tobe replicated to a target volume at a target site through the use of areplication appliance; wherein the API is enabled to create networkzones between the source site and the target site for replication fromthe source site to the target site and wherein the network zone isconfigured to include the replication appliance; wherein the API isenabled to mask storage devices used to store data on the source volumeand the target volume to a respective replication appliance clusternode.
 14. The computer program product of claim 13, wherein the codefurther enables: determining connectivity of one or more replicationappliances, wherein the replication appliances include the replicationappliance, and storage arrays; wherein at least a first storage array ofthe storage arrays is on the source site and wherein at least a secondstorage array of the storage arrays is on the target site; and whereinthe storage arrays comprise the storage devices; and determiningconfigurations of the one or more storage arrays and one or morereplication volumes to match an API request for protecting the sourcevolume with the target volume inputted to the orchestration API.
 15. Thecomputer program product of claim 14 wherein the orchestration API isenabled to create the source volume on the first storage array andcreating the target volume on the target site by interacting with thefirst storage array on the source site and the second storage array onthe target site through a common storage interface.
 16. The computerprogram product of claim 15 wherein an API request to the orchestrationAPI to create a replicated volume with a set of parameters is enabled tofunction with a required set of parameters consisting essentially of thestorage size, storage protocol, and source location.
 17. The computerprogram product of claim 14 wherein the orchestration API is enabled todetermine a best set of the configurations of the one or more storagearrays and one or more replication volumes; wherein if the best set is aset of one the orchestration API uses that configuration for thereplication; and wherein if the best set has multiple configurationsrequesting input as to which configuration to use in the replication.18. The computer program product of claim 16 wherein the API request isenabled to function with a set of parameters including a target site;wherein a determination is made whether the target site has beenincluded in the API request; and wherein the API is enabled to choosethe target site based on a negative determination of target siteincluded.